WASHINGTON (AP) -- The government approved a more accurate test
for hepatitis C Friday, a move that could help blood banks more
accurately track people who may have caught the dangerous liver
virus from pre-1992 blood transfusions.

An estimated 3.9 million Americans have hepatitis C, thousands
of whom caught it from transfusions before purity tests of the
blood supply began in 1992.

So under new government rules, blood banks are testing leftover
samples of pre-1992 transfusions. When a test indicates a batch of
blood could have contained hepatitis C, hospitals will track people
who received that blood and urge them to be checked for
infection.

The test that blood banks have had to use until now sometimes
classified blood samples as ``indeterminate'' -- it couldn't always
rule out infection in samples that were fine. That meant thousands
of people who aren't sick could be scared into getting an
unnecessary hepatitis test.

The new test, Chiron Corp.'s RIBA HCV 3.0, is more accurate, the
Food and Drug Administration said Friday. In one study in which a
competing test declared 30 percent of samples indeterminate, the
RIBA 3.0 found only 7 percent inconclusive.